Antenna arrays are used for a variety of different applications. Antenna arrays may be constructed using a plurality of three-dimensional (3D) antennas. These arrays are typically configured as a rectangular lattice but other geometries are also possible. Additionally, these antennas may be used separately, and not as part of an array. In certain embodiments, the 3D antennas may comprise notch antenna elements. The term “notch antenna” is intended to include tapered and flared elements, such that the shape is not limited by this disclosure.
Each notch antenna element includes an electrically conductive body, referred to as a notch radiator element, which has a vertical gap. The vertical gap separates the notch radiator element into two prongs. Each of the prongs are energized with signals with unequal phases. In general, the energized prongs convey energy from a feed port into free space or air, or visa-versa. The feed ports may have a characteristic impedance relative to the system impedance for maximum power transfer. The propagating signal leaving the feed ports is in communication with the prongs where electrical energy is emitted into the tuned vertical gap between the two prongs. This gap is optimized with other dimensions to result in optimal performance over the designed frequency band and scan volume (array). The vertical gap conveys the propagating signal to free space or air. The antenna feed port may convey energy to and from the antenna system at its characteristic impedance.
A coincident phase centered (CPC) antenna has two such notch antennas that share a common vertical gap. Often, the notch antennas are oriented perpendicular to one another. These may be referred to as horizontally and vertically polarized antennas. These CPC antennas can be used in a variety of applications. For example, in one embodiment, only the notch antennas oriented in one direction, such as the horizontally polarized antennas, are utilized. In another embodiment, the two sets of notch antennas are used, however they are not deployed simultaneously. In yet other embodiments, the two sets of the notch antennas have been used simultaneously.
Wideband CPC antennas are used in a variety of applications. Their complex architecture makes them relatively costly to build since the quintessential CPC is formatted in a brick architecture.
Therefore, it would be beneficial if there were a coincident phase centered antenna that was more cost efficient to implement, with greater flexibility in design while retaining full functionality of the CPC antenna.